Army intelligence officers suspected that a Syrian and admitted jihadist who was detained at Abu Ghraib prison outside Baghdad knew about the illegal flow of money, arms and foreign fighters into Iraq. But he was smug, the officers said, and refused to talk. So last November, they devised a special plan for his interrogation, going beyond what Army rules normally allowed.

An Army colonel in charge of intelligence-gathering at the prison, spelling out the plan in a classified cable to the top U.S. military officer in Iraq, said interrogators would use a method known as "fear up harsh," which military documents said meant "significantly increasing the fear level in a security detainee." The aim was to make the 31-year-old Syrian think his only hope in life was to talk, undermining his confidence in what they termed "the Allah factor."

According to the plan, interrogators needed the assistance of military police supervising his detention at the prison, who ordinarily play no role in interrogations under Army regulations. First, the interrogators were to throw chairs and tables in the man's presence at the prison and "invade his personal space."

Then the police were to put a hood on his head and take him to an isolated cell through a gantlet of barking guard dogs; there, the police were to strip-search him and interrupt his sleep for three days with interrogations, barking and loud music, according to Army documents. The plan was sent to Lt. Gen. Ricardo Sanchez.

A spokesman for Sanchez declined to comment yesterday, and so it remains uncertain whether the plan was one of 25 requests for unusually tough interrogations that Army officials in Washington have said he approved between October and the present. All involved prolonged isolation of detainees, the officials said on Friday, adding that Sanchez last week issued an order barring requests for approval of particularly severe questioning tactics.

But the fact that a plan for such intense and highly organized pressure was proposed by Col. Thomas M. Pappas -- a senior military intelligence officer in Iraq who took his job at the insistence of a general dispatched from the Pentagon -- suggests a wider circle of involvement in aggressive and potentially abusive interrogations of Iraqi detainees, encompassing officers higher up the chain of command, than the Army has previously detailed.

While the Army has blamed the physical abuses documented in soldiers' photographs on a handful of night-shift soldiers at Abu Ghraib who ignored rules on humane treatment, government officials and humanitarian experts say the order indicates the abuses could instead have been an outgrowth of harsh treatment that had been approved.

They suggest in particular that military intelligence officials may not only have improperly tolerated physical abuses, as stated in the Army's official internal report, but also that they may have deliberately set the stage for them. According to a hypothesis now being explored by members of Congress, this stage was set through a directed collaboration between two units of military police and intelligence officers, virtually unprecedented in recent Army practice.

The interrogation plan for the Syrian "clearly allows for a crossing of the line into abusive behavior," said James Ross, a senior legal adviser to Human Rights Watch who reviewed it for The Washington Post.

What makes its wording so troubling, Ross added, is that it allows "wide authority for soldiers conducting interrogations. . . . Were the superior officer to agree to these techniques, it would be opening the door for any soldier or officer to be committing abusive acts and believe they were doing so" with official sanction.

Congressional testimony by Defense Department and Army officials over the past two weeks has highlighted the fact that the abuses in Iraq -- which mostly occurred in the last quarter of 2003 -- came at a time of heightened pressures in Washington for more robust intelligence-gathering, because of proliferating attacks on U.S. forces and the dwindling intelligence on Saddam Hussein's suspected weapons of mass destruction.

Although no direct links have been found between the documented abuses and orders from Washington, Pentagon officials who spoke on the condition that they not be named say that the hunt for data on these two topics was coordinated during this period by Defense Undersecretary Stephen A. Cambone, the top U.S. military intelligence official and long one of the closest aides to Secretary of Defense Donald H. Rumsfeld.

The coincidence in timing has in turn prompted several lawmakers to say they intend to probe more deeply in coming weeks to determine whether the specialists and sergeants handling the prison guard dogs and pulling hoods over prisoners' heads were in fact implementing policy directives instigated by Washington that may have set the stage for abuses.

"We've got no proof that a person in authority told them to do this activity," Lt. Gen. Keith Alexander, the Army's deputy chief of staff, said on May 11.